The present invention is related to interconnected networks and pertains particularly to automated internet protocol (IP) address allocation and assignment for the internet protocol.
The Transport Control/Internet Protocol (TCP/IP) has entered the main stream as the protocol of choice for network connectivity. TCP/IP commonly referred to as IP, has a number of benefits which attract networks and users including standardization, rich protocol and application support and the ability to route over Wide Area Networks (WANs). There are a variety of ways to configure and set up an IP protocol stack. IP is flexible in that the protocol stack may be configured manually on the host, or automatically which minimizes the level of interaction by the network administrator.
Although IP has many benefits, because the protocol stack often needs to be manually configured, IP can be difficult to configure and administer. This is especially the case in environments where a network novice may be present. The steps required to setup and configure an IP host are not intuitive. A TCP/IP knowledgeable person is required to provide the basic configuration information. A person familiar with TCP/IP but not familiar with the network cannot properly configure IP since the currently available set of addresses, a subnet mask and default gateway are required. Implementation difficulties are further exacerbated by the fact that errors occurring during IP installation can cause severe network problems and can be difficult to solve.
For basic IP configuration, an IP address is selected and configured on the host entity. Selection of an IP address requires that the user know a unique address which corresponds to the network where the host entity is to operate. IP addresses are sometimes managed by a system administrator in order to guarantee uniqueness. Also, an IP subnet mask must be selected and configured on each host entity. Selection of the IP subnet mask is required so that it can be determined when an address in the host's protocol stack is meant for the local subnet and when an address should be passed to the default gateway. Optionally, IP configuration may include the selection and configuration of a default gateway on the host entity. In order to allow communication across multiple networks, the default gateway must be configured.
One method of defining IP configuration information is through the usage of a BOOTstrap Protocol (BOOTP). BOOTP allows clients to automatically receive all IP configuration information from a configured BOOTP server. This frees the user from having to configure individual entities but the BOOTP server itself needs to be configured.
Because the BOOTP server configuration requires assignment of unique IP addresses by the system administrator, it is administratively expensive and more prone to error than more automatic configuration methodologies. When a client sends unique MAC (Media Access Controller) address to the BOOTP server, the BOOTP server sends the client a IP address.
Another method of defining IP configuration information is through the usage of a Dynamic Host Configuration Protocol (DHCP). DHCP provides a framework for passing configuration information to hosts on a TCP/IP network. DHCP is based on BOOTP, but goes beyond it by adding the capability of automatic allocation of reusable addresses and configuration options. Like BOOTP, the configuration for individual entities must be configured on the DHCP server. DHCP reuses IP addresses but does not address the issue of friendly names associated with initiated addresses and how their associations may change.
One of the problems associated with both BOOTP and DHCP is the requirement of a BOOTP or DHCP server for assignment of IP addresses. A third protocol, AutoIP allows devices to claim IP addresses in the absence of a DHCP server or similar IP configuration authority. IP addresses are assigned from a reserved range of addresses that are only good for the local network. An unconfigured device will claim an address in the reserved range of addresses by randomly generating an address in the reserved range and then making an ARP request to see if the address has already been claimed by another device. AutoIP continually check for the presence of a DHCP server. If a DHCP server comes online, the previously configured AutoIP devices will attempt to switch their IP addresses to one provided by the DHCP server.
A network configuration and method is needed for transferring and/or assigning IP address and network information to devices that are connected to a network (which may or may not include a server) which works with current protocols, minimizes user and system administrator interaction, and minimizes the need for specialized software services.